Substituted pyrazolyl-pyrazole derivatives, processes for their preparation and their use as agents with herbicidal action

ABSTRACT

The invention relates to new substituted pyrazol derivatives of general formula (I) in which: R 1 , R 2 , R 3 , R 4 , R 5  and R 6  have the meanings given in the description, agents with herbicidal action containing at least one compound of formula (I), and their use as herbicides.

This application is a divisional of application U.S. Ser. No. 08/809,391, filed on Apr. 22, 1997, now allowed, which is a national phase application filed 35 U.S.C. 371 of international application PCT/EP95/03732 which has an international filing date of Sep. 21, 1995.

The invention concerns new substituted pyrazolyl-pyrazole derivatives, their preparation as well as intermediate products for their preparation, and their use as agents with herbicidal action.

It is already known that pyrazoles possess herbicidal properties (WO 940899). It frequently occurs however that the herbicidal action of the known compounds is not sufficient or selectivity problems occur with the relevant herbicidal action in main agricultural crops.

The problem of the present invention is to prepare new substituted pyrazole derivatives which do not exhibit these disadvantages and whose biological properties are superior to those of the currently known compounds.

It has now been found that substituted pyrazole derivatives of the general formula (I) have a superior herbicidal action: ##STR1## in which R¹ =C₁ -C₄ alkyl,

R² =C₁ -C₄ alkyl, C₁ -C₄ alkylthio, C₁ -C₄ alkoxy; or C₁ -C₄ alkyl, C₁ -C₄ alkylthio, C₁ -C₄ alkoxy all substituted one or more times with halogen,

R¹ and R² together form the group --(CH₂)_(m) --,

R³ =hydrogen or halogen,

R⁴ =hydrogen or C₁ -C₄ alkyl,

R⁵ =hydrogen, nitro, cyano or the groups --COOR⁷, ##STR2## R⁷, R⁸ and R⁹, independent of one another, are hydrogen or C₁ -C₄ alkyl,

R⁸ and R⁹, together with the adjacent nitrogen atom, form a 5-membered or 6 -membered saturated heterocyclic ring,

R¹⁰ =hydrogen, C₁ -C₄ alkyl, or a C₁ -C₄ alkyl substituted one or more times by halogen,

R¹¹ =hydrogen, C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl;

or C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl all substituted similarly or differently one or more times by halogen, hydroxy or C₁ -C₄ alkoxy;

or C₂ -C₈ alkyl, C₃ -C₆ cycloalkyl, C₃ -C₈ alkenyl, C₃ -C₆ alkynyl all interrupted one or more times by oxygen; or the group OR¹²,

R¹² =hydrogen, C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl; C₁ -C₆ alkyl substituted similarly or differently one or more times by halogen, hydroxy or C₁ -C₄ alkoxycarbonyl, C₁ -C₄ alkyl or C₁ -C₄ alkoxy,

Y=oxygen, sulphur, --N--OR¹³ and ##STR3## R¹³ =hydrogen, C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl;

C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl all substituted similarly or differently one or more times by halogen, cyano, hydroxy or C₁ -C₄ alkoxy;

C₂ -C₈ alkyl, C₃ -C₈ cycloalkyl, C₃ -C₈ alkenyl, C₃ -C₈ alkynyl all interrupted one or more times by oxygen;

C₁ -C₄ alkoxycarbonyl-C₁ -C₄ alkyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl-C₂ -C₄ alkenyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl,

R¹⁴ and R¹⁵, independent of one another, are hydrogen, halogen, cyano, carboxyl, formyl, C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl;

C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl all substituted similarly or differently one or more times by halogen, cyano, hydroxy or C₁ -C₄ alkoxy;

C₂ -C₈ alkyl, C₃ -C₈ cycloalkyl, C₃ -C₈ alkenyl, C₃ -C₈ alkynyl all interrupted one or more times by oxygen;

C₁ -C₄ alkoxycarbonyl-C₁ -C₄ alkyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl-C₂ -C₄ alkenyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl, C₁ -C₄ alkoxy or C₁ -C₄ alkylthio,

R¹⁴ and R¹⁵ together with the carbon atom form a saturated carbocyclic C₃ -C₆ ring which can be interrupted one or more times by oxygen or sulphur,

R¹⁶ =hydrogen or C₁ -C₄ alkyl,

R¹⁷ =hydrogen, C₁ -C₄ alkyl or halogen-C₁ -C₄ alkyl,

R¹⁸, R¹⁹, R²⁰, R²¹, R²² and R²³, independent if one another, are hydrogen, halogen, C₁ -C₄ alkyl, C₂ -C₄ alkenyl or C₃ -C₄ alkynyl;

C₁ -C₄ alkyl, C₂ -C₄ alkenyl, C₃ -C₄ alkynyl, carboxyl or C₁ -C₄ alkoxycarbonyl all substituted similarly or differently one or more times by halogen, cyano, nitro, hydroxy or by C₁ -C₄ alkoxy,

R²⁴ =C₁ -C₄ alkyl, or C₁ -C₄ alkyl substituted one or more times by halogen,

m=3 or 4,

n=0, 1, 2 or 3,

p=0 or 1,

X=oxygen or sulphur,

Z=oxygen, sulphur or N--R²⁵,

R²⁵ =hydrogen or C₁ -C₄ alkyl,

W=oxygen, sulphur or carbon.

The term "halogen" includes fluorine, chlorine and iodine.

The term "alkyl", "alkylene" and "alkynyl" implies that the carbon chain can be branched or unbranched.

The compounds of formula (I) which are preferred are those wherein:

R¹ =methyl,

R² =methylthio or difluormethoxy,

R¹ and R² together form the group --(CH₂)₄ --,

R³ =hydrogen, chlorine or bromine,

R⁴ =hydrogen,

R⁵ =hydrogen, nitro, cyano or the groups --COOR⁷ or --CXR¹⁰,

R⁶ = ##STR4## or one of the groups ##STR5## R⁷ =hydrogen or C₁ -C₄ alkyl, R¹⁰ =hydrogen, C₁ -C₄ alkyl, or a C₁ -C₄ alkyl substituted one or more times by halogen,

R¹¹ =hydrogen, C₁ -C₆ alkyl or the group --OR¹²,

R¹² =C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl; a C₁ -C₆ alkyl substituted similarly or differently one or more times by halogen, hydroxy or C₁ -C₄ alkoxy,

Y=oxygen, sulphur, --N--OR¹³ and ##STR6## R¹³ =hydrogen, C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl;

C₂ -C₈ alkyl, C₃ -C₈ cycloalkyl, C₃ -C₈ alkenyl, C₃ -C₈ alkynyl all interrupted one or more times by oxygen;

C₁ -C₄ alkoxycarbonyl-C₁ -C₄ alkyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl-C₂ -C₄ alkenyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl,

R¹⁴ and R¹⁵, independent of one another, are hydrogen, halogen, cyano, carboxyl, formyl,

C₁ -C₆ alkyl, C₃ -C₆ cycloalkyl, C₂ -C₆ alkenyl, C₃ -C₆ alkynyl;

C₁ -C₄ alkoxycarbonyl-C₁ -C₄ alkyl, which can optionally be substituted by halogen atoms;

C₁ -C₄ alkoxycarbonyl, C₁ -C₄ alkoxy or C₁ -C₄ alkylthio,

R¹⁶ =hydrogen or C₁ -C₄ alkyl,

R¹⁷ =hydrogen, C₁ -C₄ alkyl or halogen-C₁ -C₄ alkyl,

R¹⁸, R¹⁹, R²⁰, R²¹, R²² and R²³, independent if one another, are hydrogen, halogen, C₁ -C₄ alkyl, C₂ -C₄ alkenyl or C₃ -C₄ alkynyl;

C₁ -C₄ alkyl, C₂ -C₄ alkenyl, C₃ -C₄ alkynyl, carboxyl or C₁ -C₄ alkoxycarbonyl all substituted similarly or differently one or more times by halogen, cyano, nitro, hydroxy or by C₁ -C₄ alkoxy,

R²⁴ =C₁ -C₄ alkyl, or C₁ -C₄ alkyl substituted one or more times by halogen,

m=3 or 4,

n=0, 1, 2 or 3,

p=0 or 1,

X=oxygen or sulphur,

Z=oxygen, sulphur or N--R²⁵,

R²⁵ =hydrogen or C₁ -C₄ alkyl,

W=oxygen, sulphur or carbon.

Especially preferred are such compounds of formula (I) in which

R¹ =methyl,

R² =difluormethoxy,

R¹ and R² together form the group --(CH₂)₄ --,

R³ =chlorine,

R⁴ =hydrogen,

R⁵ =nitro or cyano,

R⁶ = ##STR7## or the group ##STR8## R¹¹ =hydrogen or the group --OR¹², R¹² =C₁ -C₆ alkyl,

Y=oxygen, --N--OR¹³ and ##STR9## R¹³ =C₁ -C₆ alkyl, R¹⁴ and R¹⁵, independent of one another, are hydrogen, halogen or C₁ -C₆ alkoxy,

R¹⁶ =hydrogen,

R¹⁷ =hydrogen,

R¹⁸, R¹⁹, R²⁰, R²¹, R²² and R²³ , independent if one another, are hydrogen, halogen, C₁ -C₄ alkyl, C₁ -C₄ -alkoxycarbonyl-C₁ -C₄ -alkyl, or C₁ -C₄ -haloalkyl,

n=0,

p=0 or 1, and

X=oxygen.

The compounds of the general formula (I) according to the invention can be prepared as follows:

A) a compound of the general formula (II) ##STR10## in which R¹, R² and R³ have the meanings given in the general formula (I), is reacted with a compound of the general formula (III) ##STR11## in which R⁵ stands for the group --COOR⁷ or the group ##STR12## whereby R⁷, R⁸ and R⁹ have the meaning given in the general formula (I) and X stands for oxygen, R⁶ has the meaning given in the general formula (I) but contains no formyl groups and B stands for the group --OR²⁶ or ##STR13## whereby R²⁶, R²⁷ and R²⁸ independent of one another mean C₁ -C₄ alkyl, or

B) in the case where R⁶ stands for the formyl group, a compound of the general formula (Ia) ##STR14## in which R¹, R², R³, R⁴ and R⁵ have the meaning given in the general formula (I), and A stands for hydrogen, halogen, hydroxy, an alkyl- or aryl-sulphonyl group, is reacted with a suitable oxidising agent, or

C) in the case where R⁶ stands for the group --CYR¹¹, whereby R¹¹ has the meaning given in the general formula (I) and Y stands for oxygen, a compound of the general formula (Ib) ##STR15## in which R¹, R², R³, R⁴ and R⁵ have the meaning given in the general formula (I), is metallised with a suitable base and is then (reacted) with an acyl compound of the general formula IV or V ##STR16## in which R¹¹ has the meaning given in the general formula (I) and D stands for chlorine, bromine, --OR²⁹ or ##STR17## whereby R²⁹, R³⁰ and R³¹ stand for C₁ -C₄ alkyl. Should R¹¹ stand for hydrogen, then the meaning of D is constrained to --OR²⁹ and to ##STR18## or, D) in the case where R⁶ stands for the group ##STR19## in which R¹¹ has the meaning given in the general formula (I) and Y stands for sulphur, a compound of the general formula (Ic) ##STR20## in which R¹, R², R³, R⁴, R⁵ and R¹¹ have the meaning given in the general formula (I), is reacted with Lawessons reagent, or

E) in the case where R⁶ stands for the group ##STR21## in which R¹¹ has the meaning given in the general formula (I) and Y stands for the group --N--OR¹³, in which R¹³ has the meaning given in the general formula (I), a compound of the general formula (Ic) ##STR22## in which R¹, R², R³, R⁴, R⁵ and R¹¹ have the meaning given in the general formula (I), is reacted with a compound of the general formula VI

    H.sub.2 N--OR.sup.13                                       VI

in which R¹³ has the meaning given in the general formula (I), or

F) in the case where R⁶ stands for the group ##STR23## in which R¹¹ has the meaning given in the general formula (I) and Y stands for ##STR24## whereby R¹⁴ and R¹⁵ have the meaning given in the general formula (I), a compound of the general formula (Ic) ##STR25## in which R¹, R², R³, R⁴, R⁵ and R¹¹ have the meaning given in the general formula (I), is reacted with a compound of the general formula VII or VIII ##STR26## in which R¹⁴ and R¹⁵ have the meaning given in the general formula (I) and where R³² stands for C₁ -C₄ alkyl, or

G) in the case where R⁶ stands for halogen, a compound of the general formula (Id) ##STR27## in which R¹, R², R³, R⁴, R⁵ and R⁶ have the meaning given in the general formula (I), is reacted with a suitable halogenating agent, or

H) in the case where R⁶ stands for one of the groups ##STR28## in which R¹⁶, R¹⁷, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, R²⁴, n, p and W have the meaning given in the general formula (I), a compound of the general formula (Ie) ##STR29## in which R¹, R², R³, R⁴, R⁵, R¹⁶, R¹⁷ and n have the meaning given in the general formula (I), is reacted with a compound of the general formula IX, X or XI ##STR30## in which R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, R²⁴, p and W have the meaning given in the general formula (I), or

I) in the case where R⁶ stands for the group ##STR31## in which R¹⁶, R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, n and p have the meaning given in the general formula (I), a compound of the general formula (If) ##STR32## in which R¹, R², R³, R⁴, R⁵, R¹⁶ and n have the meaning given in the general formula (I), is reacted with a compound of the general formula XII ##STR33## where R¹⁸, R¹⁹, R²⁰, R²¹, R²², R²³, Z and p have the meaning given in the general formula (I), or

J) a compound of the general formula (Ig) ##STR34## in which R¹, R², R³, R⁴ and R⁵ have the meaning given in the general formula (I), is firstly diazotised to give a compound of the general formula (Ih) ##STR35## in which R¹, R², R³, R⁴ and R⁵ have the meaning given in the general formula (I), and is then reacted with a Michael-acceptor of the general formula XIII ##STR36## in which R³³ and R³⁴, independent of one another, mean hydrogen, C₁ -C₄ alkyl or halogen, and R³⁵ means C₁ -C₄ alkyl, or

K) a compound of the general formula (If) is esterified with an alcohol of the general formula XIV

    R.sup.12 --OH                                              XIV

in which R¹² has the meaning given in the general formula (I).

The compounds of the general formula (I) according to the invention, in which R⁵ stands for the groups --COOR⁷ or --CXNR⁸ R⁹, can be prepared by the process described by Bisagni et al in Tetrahedron, 29, 435 (1973).

The oxidation according to process variant B) may be carried out by the processes such as are described for example in Houben-Wehl, Vol VII, 1, page 135 et seq (1954) or in Vol E3, page 231 et seq (1983). The compounds of general formula (Ia) used as starting materials are known (WO 94 08 999).

The process variant C) is carried out effectively by reacting the starting material of formula (Ib) in a suitable solvent at a temperature from -100 to +40° C. with a suitable base to give a compound of the general formula (Ii) ##STR37## in which R¹, R², R³, R⁴ and R⁵ have the meaning given in the general formula (I) and metal.sup.⊕ stands for a metal cation such as for example lithium, sodium or potassium. The intermediate compound of the formula (Ii) is reacted directly, i.e., without any further processing, with a compound of formula IV or V at a temperature from -100 to +100° C.

Ethers, such as for example diethyl ether, tetrahydrofuran or 1,4-dioxane, may be cited as suitable solvents.

Butyl lithium, lithium diisopropylamide, sodium hydride or potassium tert. butylate may be cited as bases.

The compounds of the general formula (Ib) used as starting materials are known. Their preparation is described in WO 94 08 999.

The process variant D) can be carried out for example according to the methods described in Bull Soc Chim Belg, 87, 223, 229, 299 or 525, (1978).

The formation of oxime-ether in process variant E) can be carried out according to known processes such as are described for example in Houben-Wehl, Vol X4, page 55 et seq (1968).

The compounds involved in process variant F) can be prepared by the methods described in "Advanced Organic Chemistry", 1985, page 864 et seq and in the literature cited therein.

Sulphuryl chloride, sodium hypochlorite, N-chlorosuccinimide, N-bromosuccinimide, chlorine or bromine are examples of halogenating agents which may be used.

The acetals or ketals may be prepared by the methods described by T W Greene in "Protective Groups in Organic Synthesis", 1980, page 116 et seq.

The compounds according to the invention in accordance with process variant I) can be prepared by the process described by A I Meyers in J Am Chem Soc, 92, 6644 (1970).

The compounds according to the process variant J) can be prepared according to the process cited in U.S. Pat. No. 5,250,504.

The esterfications according to the last process stage are known per se and they can be carried out according to the usual methods, such as for example those described in Houben-Wehl, Vol E5, page 659 et seq (1985).

The preparation can be carried out with or without solvents whereby if necessary such solvents or diluents which are inert with regard to the respective reactants may be used. Examples of such solvents or diluents respectively are aliphatic and aromatic hydrocarbons each of which may optionally be chlorinated, such as for example hexane, cyclohexane, petroleum ether, white spirit, benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethylene and chlorobenzene; ethers such as for example diethyl ether, methyl ethyl ether, methyl t-butyl ether, diisopropyl ether, dibutyl ether, dioxane and tetrohydrofuran; ketones such as for example acetone, methyl ethyl ketone, methylisopropyl ketone, methylisobutyl ketone; nitriles such as for example acetonitrile and propionitrile; alcohols such as for example methanol, ethanol, isopropanol, butanol, tert-butanol, tert-amyl alcohol and ethylene glycol; esters such as for example ethyl acetate and amyl acetate, acid amides such as for example dimethyl formamide and dimethyl acetamide, sulphoxides such as for example dimethyl sulphoxide, sulphones such as for example sulpholane, bases such as for example pyridine and triethylamine, carboxylic acids such as for example acetic acid, and mineral acids such as for example sulphuric acid and hydrochloric acid.

The usual procedures are used for working-up the compounds according to the invention. Purification is carried out by crystallisation or by column chromatography.

The compounds according to the invention are generally colourless or slightly yellow-coloured crystalline or viscous substances which for the most part are readily soluble in chlorinated hydrocarbons, such as for example methylene chloride or chloroform, ethers such as for example diethyl ether or tetrahydrofuran, alcohols such as for example methanol or ethanol, ketones such as for example acetone or butanone, amides such as for example dimethylformamide and also sulphoxides such as for example dimethyl sulphoxide.

The compounds according to the invention display good herbicidal action on broad-leaved weeds and grasses. Selective application is possible with various crops, for example rape, beet, soya beans, cotton, rice, maize, barley, wheat and other kinds of cereals. Individual compounds are also suitable as selective herbicides for beet, cotton, soya, maize and cereal. Furthermore the compounds can be used for weed-killing during long-term cultivation such as for example in plantations for forestry, decorative wood, fruit, wine, citrus, nuts, bananas, coffee, tea, rubber, oilpalm, cocoa, fruit berries and hops.

The compounds according to the invention can be used for example for the following plant species:

Dicotyledonous weeds of genus such as Sinapis, Lepidium, Galium, Stellaria, Matricaria, Anthemis, Galinsoga, Chenopodium, Brassica, Urtica, Senecio, Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum, Sesbania, Ambrosia, Cirsium, Sonchus, Solanum, Lamium, Veronica, Abutilon, Datura, Viola, Galeopsis, Papaver, Centaurea and Chrysanthemum; monocotyledonous weeds of genus such as Avena, Alopecurus, Echinochloa, Sataria, Panicum, Digitaria, Poa, Eleusine, Brachiaria, Lolium, Bromus, Cyperus, Elymus, Sagittaria, Monochoria, Fimbristylis, Eleocharis, Ischaemum and Apera.

The applied amounts vary depending on the type of use and the stage of growth between 0.001 and 5 kg/ha.

The active agents according to the invention can also be used as defoliants, desiccants and weed-killing agents.

Enhancement of the intensity of action and the speed of action can be achieved for example by the use of additives which magnify the effect, such as organic solvents, wetting agents and oils. The use of such additives therefore optionally leads to a reduction in the dosage of the active material.

The active agents according to the invention or their mixtures are desirably applied in the form of preparations such as powders, spreading agents, granulates, solutions, emulsions or suspensions, with the addition of liquid and/or solid carriers or diluents respectively and optionally with bonding agents, wetting agents, emulsifying agents and/or dispersion aids.

Suitable liquid carriers are for example aliphatic and aromatic hydrocarbons such as benzene, toluene, xylene, cyclohexanone, isophorone, dimethyl sulphoxide, dimethyl formamide and also mineral oil fractions and vegetable oils.

Suitable solid carriers are minerals such as for example bentonite, silica gel, talc, kaolin, Attapulgit, chalk and vegetable products such as for example flour.

Examples of surfactants are calcium lignin sulphonate, polyethylene alkylphenyl ether, naphthalene sulphonic acids and their salts, phenol sulphonic acids and their salts, condensates of formaldehyde, fatty alcohol sulphates as well as substituted benzene sulphonic acids and their salts.

The amount of the respective active agent(s) in the various preparations can vary over a wide range. For example, the material contains about 10 to 90 weight % active agent, about 90 to 10 weight % liquid or solid carrier and optionally up to 20 weight % surfactant.

Application of the material can occur in the usual way, for example with water as the carrier in spraying amounts of about 10 to 1000 liter/ha. Application of the material in the so-called Low-Volume-Process and the Ultra-Low-Volume-Process is also possible as is its application in the form of so-called micro-granules.

The preparation of these mixtures can be carried out in a way known per se, for example by milling or mixing processes. If desired, preparations of the individual components can be mixed shortly before their use, as carried out in practice for example in the so-called tank-mix process.

The following Examples describe the preparation of the compounds according to the invention.

EXMAPLE 1 (PROCESS B) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-formyl-4-pyrazol-carbonitrile

29 g (9.6 mmol) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-hydroxymethyl-4-pyrazol-carbonitrile is added to 30 ml dichloromethane and 15.2 g pyridinium chlorochromate on aluminium oxide is then added. Stirring continues for 1 hour at room temperature and then the reaction mixture is vacuum filtered through Celite and purified by means of column chromatography using hexane/ethyl acetate.

Yield: 1.8 g=62% of theory

n_(D) ²⁰ =1.54066

EXAMPLE 2 (Process E) (E/Z) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-methoxyiminomethyl-4-carbonitrile

0.46 g (1.5 mmol) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-formyl-4-pyrazol-carbonitrile is added to 4 ml pyridine at room temperature and 0.25 g (3.0 mmol) O-methyl-hydroxylamine hydrochloride is added. The mixture is stirred for 2 hours at room temperature, poured into water and shaken with ethyl acetate. It is dried over magnesium sulphate and concentrated. Purfication is by column chromatography using hexane/ethyl acetate.

Yield: 0.3 g=60% of theory

Freeze point: 95-98° C.

EXAMPLE 3 (Process F) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-(2-methoxyvinyl)-4-pyrazol-carbonitrile

2.9 g (8.4 mmol) methoxymethylene-triphenylphosphonium chloride is added to 10 ml tetrahydrofuran and 5.6 ml (9.0 mmol) of a 1,6 molar solution of butyl lithium in hexane is slowly added dropwise at 0° C. The orange-coloured solution is stirred for another 30 minutes and then 1.0 g (3.3 mmol) 1-(4chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-formyl-4-pyrazol-carbonitrile is slowly added dropwise. Stirring continues for 2 hours at room temperature. The reaction mixture is then added to water, shaken with ethyl acetate, dried over magnesium sulphate and concentrated. Purification is by column chromatography using a hexane/ethyl acetate mixture.

EXAMPLE 4 (Process H) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-(1,3-dioxolan-2-yl)-4-pyrzol-carbonitrile

0.6 g (2.0 mmol) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-formyl-4-pyrazol-carbonitrile is dissolved in 30 ml toluene and 0.14 g (2.2 mmol) ethylene glycol and a catalytic amount of p-toluene sulphonic acid are added. The mixture is heated for 2 hours on the water-separator, the cooled solution is washed with sodium chloride solution, and it is then dried and concentrated.

Yield: 0.68 g=98% of theory

Freeze point: 70-72° C.

EXAMPLE 5 (Process H) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-(1,1-diacetoxymethyl)-pyrazol-4-carbonitrile

5 ml acetic anhydride is cooled to 0-5° C. and 2 drops boron trifluoride-etherate are added. Then 2.3 g (7.6 mmol) 1-(4-chlor-5-difluormethoxy-1-methyl-3-pyrazolyl)-5-formyl-4-pyrazol-carbonitrile is slowly added dropwise and stirring is continued for another 1.5 hours at room temperature. 9 ml of 10% sodium acetate solution is added, stirring is continued for 20 minutes at room temperature and then the mixture is shaken up with ethyl acetate. The combined ethyl acetate phases are washed with a solution of sodium hydrogen carbonate and sodium chloride, dried and concentrated. Purification is by column chromatography using a hexane/ethyl acetate mixture.

Yield: 2.5 g=80% of theory

Freeze point: 84-85° C.

EXAMPLE 6 (Process J) 2-chlor-3-[1-(3-chlor-4,5,6,7-tetrahydropyrazolo-[1,5a]-pyridin-2-yl)-4-cyan-5-pyrazolyl]-2-methyl-propionic acid ethyl ester

1.6 g (15.5 mmol) tert-butyl nitrite, 20 ml ethyl methacrylate and 1.52 g copper-II-chloride is added to 20 ml acetonitrile and 2.62 g (10 mmol) 5-amino-1-(3-clor-4,5,6,7-tetrahydropyrazolo-[1,5-a]-pyridin-2-yl)-4-pyrazol-carbonitrile is added in 3 portions. The mixture is stirred at room temperature for 20 hours, added to 50 ml 2N hydrochloric acid, extracted 3 times with dichloromethane, dried over magnesium sulphate and concentrated. Purification is by column chromatography using a hexane/ethyl acetate mixture.

Yield: 1.6 g=40% of theory

n_(D) ²⁰ =1.54164

EXAMPLE 7 (Process K) 1-(3chlor-4,5,6,7-tetrahydropyrazolo-[1,5-a]-pyridin-2-yl)-4-cyan-5-pyrazol-carboxylic-acid-isopropylester.

757 mg (2.7 mmol) of azodicarboxylic acid diethylester is added dropwise to 800 mg (2.7 mmol) 1-(3-chlor-4,5,6,7-tetrahydropyrazolo-[1,5-a]-pyridin-2-yl)-4-cyan-5-pyrazol-carboxylic-acid. The mixture is stirred for 2 hours at this temperature, then concentrated and purified by column chromatography using SiO₂ /hexane/ethyl acetate. The residue is recrystallised from diisopropyl ether.

Yield: 570 mg=62% of theory

n_(D) ²⁰ =1.53942

The followng compounds of formula (I) are prepared in an analogous fashion, wherein R⁴ is just hydrogen.

    __________________________________________________________________________                                      Freeze pt. [° C.]                        No. R.sup.1 R.sup.2 R.sup.3 R.sup.5 R.sup.6 or n.sub.D (°             __________________________________________________________________________                                      C.)                                             8 CH.sub.3 OCHF.sub.2 Cl CN                                                                                     148-150                                        - 9 CH.sub.3 OCHF.sub.2 Cl CN                                                                                  viscous oil                                    - 10 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 viscous oil                                    - 11 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 140-142                                        - 12 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 viscous oil                                    - 13 CH.sub.3 OCHF.sub.2 Br CN                                                                                 145 43##                                       -                                                                             14 --(CH.sub.2).sub.4 -- Cl CN                                                                                  106-108                                        - 15 --(CH.sub.2).sub.4 -- Cl CN                                                                               #STR45##                                       - 16 --(CH.sub.2).sub.4 -- Br CN                                                                               #STR46##                                       - 17 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR47##                                       -                                                                             18 CH.sub.3 OCHF.sub.2 Cl CN                                                                                    #STR48##                                       - 19 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR49##                                       - 20 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR50##                                       - 21 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR51##                                       - 22 CH.sub.3 OCHF.sub.2 Br CN                                                                                 #STR52##                                       - 23 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR53##                                       - 24 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR54##                                       - 25 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR55##                                       -                                                                             26 --(CH.sub.2).sub.4 -- Cl CN                                                                                  #STR56##                                       - 27 --(CH.sub.2).sub.4 -- Cl CN                                                                               #STR57##                                       - 28 --(CH.sub.2).sub.4 -- Cl CN                                                                               #STR58##                                       - 29 --(CH.sub.2).sub.4 -- Br CN                                                                               #STR59##                                       - 30 --(CH.sub.2).sub.4 -- Br NO.sub.2                                                                         #STR60##                                       -                                                                             31 CH.sub.3 OCHF.sub.2 Cl CN                                                                                    115-117                                        - 32 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 1.5327 (20)                                    - 33 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR63##                                       - 34 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 1.515 (20.1)                                   - 35 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR65##                                       - 36 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR66##                                       - 37 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 #STR67##                                       - 38 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2 CH.sub.3 131-132                    39 CH.sub.3 OCHF.sub.2 Br CN --CO.sub.2 C.sub.2 H.sub.5 72                     40 CH.sub.3 OCHF.sub.2 Cl NO.sub.2 --CO.sub.2 C.sub.2 H.sub.5                  41 CH.sub.3 OCHF.sub.2 Cl CN                                                                                    #STR68##                                      42 CH.sub.3 CCHF.sub.2 Cl CN                                                                                    #STR69##                                      43 --(CH.sub.2).sub.4 -- Cl CN --CO.sub.2 CH.sub.3 115-116                     44 --(CH.sub.2).sub.4 -- Cl CN --CO.sub.2 C.sub.2 H.sub.5 1.55882 (20)                                         45 --(CH.sub.2).sub.4 -- Cl CN --CH.sub.                                      2 CHCl--CO.sub.2 C.sub.2 H.sub.5 1.54920                                       (20)                                            46 --(CH.sub.2).sub.4 -- Cl CN --CO.sub.2 --CH.sub.2 CH.sub.2 CH.sub.3                                        83-85                                           47 --(CH.sub.2).sub.4 -- Cl CN --CH═CH--CO.sub.2 C.sub.2 H.sub.5                                          132-133                                         48 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OC.sub.2 H.sub.5                      49 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OCH.sub.2 C.tbd.CH                    50 CH.sub.3 CCHF.sub.2 Cl CN --CH═CCl.sub.2                                51 CH.sub.3 OCHF.sub.2 Br CN --CH═CBr.sub.2                                52 CH.sub.3 OCHF.sub.2 Cl NO.sub.2 --CH═N--OCH.sub.3 88-89                 53 CH.sub.3 OCHF.sub.2 Cl CN --CCH.sub.3 ═N--OCH.sub.3                     54 CH.sub.3 OCHF.sub.2 Cl CN --CH═CH--CN                                   55 --(CH.sub.2).sub.4 -- Cl CN --CCH.sub.3 ═CH--C.sub.2 H.sub.5                                            56 --(CH.sub.2).sub.4 -- Br CN --CCF.sub                                      .3 ═CH.sub.2                                57 --(CH.sub.2).sub.4 -- Cl NO.sub.2 --CH═CH--CCH.sub.3 ═CH.sub.                                      2                                               58 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OCH.sub.2 --CH═CH.sub.2                                          1.5344 (20)                                     59 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OC.sub.2 H.sub.5                       - 60 CH.sub.3 CCHF.sub.2 Cl CN                                                                                 1.5372 (20)                                    - 61 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR71##                                       - 62 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           133-134                                        - 63 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           127-128                                        - 64 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           98 R74##                                       - 65 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           73-75 ##                                       - 66 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           1.516 (20.2)                                   - 67 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR77##                                       - 68 CH.sub.3 OCHF.sub.2 Br NO.sub.2                                                                           #STR78##                                       - 69 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR79##                                       - 70 CH.sub.3 OCHF.sub.2 C1 NO.sub.2                                                                           #STR80##                                       - 71 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           108 81##                                       - 72 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR82##                                       - 73 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR83##                                       - 74 CH.sub.3 CCHF.sub.2 Cl NO.sub.2                                                                           #STR84##                                       - 75 CH.sub.3 CCHF.sub.2 Cl NO.sub.2                                                                           #STR85##                                       - 76 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR86##                                       - 77 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR87##                                       - 78 CH.sub.3 OCKF.sub.2 Br NO.sub.2                                                                           #STR88##                                       - 78 CH.sub.3 OCHF.sub.2 Br NO.sub.2 --CHO                                    80 CH.sub.3 OCHF.sub.2 Br NO.sub.2 --CH═NOCH.sub.3                          - 81 CH.sub.3 OCHF.sub.2 Cl NO.sub.2                                                                           #STR89##                                       -                                                                             82 --(CH.sub.2).sub.4 -- Cl NO.sub.2 --COOC.sub.2 H.sub.5                       - 83 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR90##                                       - 84 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR91##                                       - 85 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR92##                                       - 86 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR93##                                       - 87 --(CH.sub.2).sub.4 -- Cl NO.sub.2                                                                         #STR94##                                       - 88 --(CH.sub.2).sub.4 -- Br NO.sub.2                                                                         #STR95##                                       - 89 --(CH.sub.2).sub.4 -- Br NO.sub.2                                                                         #STR96##                                       -                                                                             90 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OCH.sub.2 COOH 178                     - 91 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 1.501 (20.1)                                   - 92 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 viscous oil                                    - 93 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 87 R99##                                       - 94 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2 C.sub.2 H.sub.5 70                  95 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OCH.sub.2 CO.sub.2 CH.sub.3 85        96 CH.sub.3 OCHF.sub.2 Cl CN --CH═N--OCH.sub.2 CO.sub.2 C.sub.2                                           H.sub.5 89                                      97 CH.sub.3 OCHF.sub.2 Cl NO.sub.2 --CHO 75-76                                  - 98 CH.sub.3 OCHF.sub.2 Cl CN                                                                                 1.529 (20.2)                                   - 99 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OCH.sub.3 88-89                     - 100 CH.sub.3 OCHF.sub.2 Br CN                                                                                1.529 (20.2)                                   - 101 CH.sub.3 OCHF.sub.2 Cl NO.sub.2 --CH═N--OCH.sub.2 CO.sub.2                                         C.sub.2 H.sub.5 85                              102 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OCH.sub.2 CO.sub.2 CH.sub.3                                         108                                             103 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OCH.sub.2 CO.sub.2 -i-C.sub.3                                       H.sub.7 102                                     104 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OCH.sub.2 CO.sub.2 CH.sub.2                                         CF.sub.3 63                                     105 CH.sub.3 OCHF.sub.2 Br CN --CH═N--OCH.sub.2 CO.sub.2 C.sub.2                                          H.sub.4 OCH.sub.3 77                            106 CH.sub.3 OCHF.sub.2 Br CN --COOH 180                                       107 CH.sub.3 OCHF.sub.2 Br CN --CO.sub.2 C.sub.2 H.sub.4 OCH.sub.3                                            1.5182 (24.0)                                   108 CH.sub.3 OCHF.sub.2 Br CN --CO.sub.2 CH.sub.2 CO.sub.2 CH.sub.3                                            109 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2                                       C.sub.2 H.sub.4 OCH.sub.3                      110 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2 CH.sub.2 CF.sub.3                     111 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2 CH.sub.2 CO.sub.2 CH.sub.3                                             - 112 CH.sub.3 OCHF.sub.2 Cl CN                                                #STR102##                                      - 113 CH.sub.3 OCHF.sub.2 Cl CN                                                                                #STR103##                                      - 114 CH.sub.3 OCHF.sub.2 Cl CN                                                                                1.521 (24)                                     - 115 CH.sub.3 OCHF.sub.2 Br CN --CO.sub.2 CH.sub.3                           116 CH.sub.3 OCHF.sub.2 Cl CN --CO.sub.2 -i-C.sub.3 H.sub.7 92-94                                               - 117 CH.sub.3 OCHF.sub.2 Cl CN                                                #STR105##                                      - 118 CH.sub.3 OCHF.sub.2 Cl CN                                                                                #STR106##                                      - 119 CH.sub.3 CCHF.sub.2 Cl CN                                                                                #STR107##                                      - 120 CH.sub.3 OCHF.sub.2 Cl CN                                                                                #STR108##                                      - 121 CH.sub.3 OCHF.sub.2 Cl CN                                                                                #STR109##                                      - 122 CH.sub.3 OCHF.sub.2 Cl CN                                                                                #STR110##                                      - 123 CH.sub.3 OCHF.sub.2 Cl CN --CO--CH.sub.3                              __________________________________________________________________________

The following Examples explain the invention:

BAYER--Code

ALOMY Alopecurus myosuroides

AGRRE Elymus repens

AVEFA Avena fatua

BROTE Bromus tectorum

SETVI Setaria viridis 0=No damage

PANSS Panicum sp. 1=1-24% damage

SORHA Sorghum halepense 2=25-74% damage

CYPES Cyperus esculentus 3=75-89% damage

ABUTH Abutilon theophrasti 4=90-100% damage

IPOSS Ipomoea purpurea

GALAP Galium aparine

MATCH Matricaria chamomilla

POLSS Polygonum Sp.

SEBEX Sesbania exaltata

SOLSS Solanum sp.

VERPE Veronica persica

VIOSS Viola sp.

EXAMPLE OF APPLICATION

The indicated plant species in the greenhouse were treated after germination with the indicated compounds in application amounts of 0.1 kg active agent/ha. For this purpose, the compounds were used as an emulsion with 500 liter water/ha and were sprayed uniformly over the plants. 2 weeks after treatment, the compounds according to the invention showed an outstanding action against weeds as is shown in the following Table.

    __________________________________________________________________________           A A A B S P S C A G I M P S S V V                                           L G V R E A O Y B A P A O E O E I                                             Compound O R E O T N R P U L O T L B L R O                                     Example M R F T V S H E T A S C S E S P S                                      No. Y E A E I S A S H P S H S X S E S                                        __________________________________________________________________________      1    --                                                                               --                                                                               --                                                                               --                                                                               3 3 --                                                                               --                                                                               4 --                                                                               4 4 4 4 4 3 3                                           3 4 3 3 -- 3 3 3 3 4 3 4 4 4 4 4 4 3                                           4 4 3 4 4 4 4 3 3 4 4 4 4 4 4 4 4 4                                            7 -- -- -- -- 3 3 -- -- 4 -- 3 3 4 4 4 3 3                                     8 4 4 4 4 4 4 3 4 4 4 4 4 4 4 4 4 4                                           12 4 3 4 4 4 3 3 4 4 4 4 4 4 4 4 4 4                                           14 3 -- -- 3 4 3 -- 3 4 4 4 4 4 4 4 4 4                                        31 4 3 3 3 3 -- -- 3 4 -- 4 4 4 4 4 4 4                                        34 4 -- 4 3 4 4 4 -- 4 4 4 4 4 4 4 4 4                                         43 -- 3 -- -- 3 3 3 -- 4 -- 4 3 4 4 4 4 3                                      44 3 -- -- -- 3 3 3 -- 4 -- 4 3 4 4 4 4 3                                      52 4 -- 3 3 4 4 3 3 4 4 4 4 4 4 4 4 4                                          62 4 -- 4 4 4 4 3 3 4 4 4 4 4 4 4 4 4                                          65 4 -- 4 3 4 4 3 4 4 4 4 4 4 4 4 4 4                                          91 4 -- 4 4 4 4 4 -- 4 4 4 4 4 4 4 4 4                                         92 4 -- 4 3 4 4 3 -- 4 4 4 4 4 4 4 4 4                                         93 4 -- 4 3 4 4 4 -- 4 4 4 4 4 4 4 4 4                                         95 -- -- -- 3 4 4 3 -- 3 4 4 4 4 4 4 4 4                                       96 -- -- 3 3 4 4 3 -- 4 4 4 4 4 4 3 4 4                                        Untreated 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0                                  __________________________________________________________________________ 

We claim:
 1. Substituted pyrazol derivatives of the general formula ##STR111## in which R¹ and R² together form the group --(CH₂)_(m) --,R³ =hydrogen or halogen, R⁴ =hydrogen or C₁ -C₄ alkyl, R⁵ =hydrogen, nitro, cyano or the groups --COOR⁷, ##STR112## R⁷, R⁸ and R⁹, independent of one another, are hydrogen or C₁ -C₄ alkyl, R⁸ and R⁹, together with the adjacent nitrogen atom, form a 5-membered or 6-membered saturated heterocyclic ring, R¹⁰ =hydrogen, C₁ -C₄ alkyl, or a C₁ -C₄ alkyl subsgituted one or more times by halogen, R¹⁶ =hydrogen or C₁ -C₄ alkyl, R¹⁷ =hydrogen, C₁ -C₄ alkyl or halogen-C₁ -C₄ alkyl, R¹⁸, R¹⁹, R²⁰, R²¹, R²² and R²³, independent of one another, are hydrogen, halogen C₁ -C₄ alkyl, C₂ -C₄ alkenyl or C₃ -C₄ alkynyl;C₁ -C₄ alkyl, C₂ -C₄ alkenyl, C₃ -C₄ alkynyl, carboxyl or C₁ -C₄ alkoxycarbonyl all substiluted similarly or differently one or more times by halogen, cyano, nitro, hydroxy or by C₁ -C₄ alkoxy, R²⁴ =C₁ -C₄ alkyl, or C₁ -C₄ alkyl substituted one or more times by halogen, m=3 or 4, n=0, 1, 2 or 3, p=0 or 1, X=oxygen or sulphur, Z=oxygen, sulphur or N--R²⁵, R²⁵ =hydrogen or C₁ -C₄ alkyl, W=oxygen, sulphur or carbon.
 2. Substituted pyrazol derivatives of the general formula (I) according to claim 1 in whichR¹ and R² together form the group --(CH₂)₄ --, R³ =hydrogen, chlorine or bromine, R⁴ =hydrogen, R⁵ =hydrogen, nitro, cyano or the groups --COOR⁷ or --CXR¹⁰, ##STR113## R⁷ =hydrogen or C₁ -C₄ alkyl, R¹⁰ =hydrogen, C₁ -C₄ alkyl, or a C₁ -C₄ alkyl substituted one or more times by halogen, R¹⁶ =hydrogen or C₁ -C₄ alkyl, R¹⁷ =hydrogen, C₁ -C₄ alkyl or halogen-C₁ -C₄ alkyl, R¹⁸, R¹⁹, R²⁰, R²² and R²³, independent of one another, are hydrogen, halogen, C₁ -C₄ alkyl, C₂ -C₄ alkenyl or C₃ -C₄ alkynyl;C₁ -C₄ alkyl, C₂ -C₄ alkenyl, C₃ -C₄ alkynyl, carboxyl or C₁ -C₄ alkoxycarbonyl all substituted similarly or differently one or more times by halogen, cyano, nitro, hydroxy or by C₁ -C₄ alkoxy, R²⁴ =C₁ -C₄ alkyl, or C₁ -C₄ alkyl substituted one or more times by halogen, n=0, 1, 2 or 3, p=0 or 1, X=oxygen or sulphur, Z=oxygen, sulphur or N--R²⁵, R²⁵ =hydrogen or C₁ -C₄ alkyl, W=oxygen, sulphur or carbon.
 3. Substituted pyrazol derivatives of the general formula (I) according to claim 1 in whichR¹ and R² together form the group --(CH₂)₄ --, R³ =chlorine, R⁴ =hydrogen, R⁵ =nitro or cyano, R⁶ = ##STR114## R¹⁶ =hydrogen, R¹⁷ =hydrogen, R¹⁸, R¹⁹, R²⁰, R²¹, R²² and R²³, independent of one another, are hydrogen, halogen, C₁ -C₄ alkyl, C₁ -C₄ alkoxycarbonyl-C₁ -C₄ alkyl, or C₁ -C₄ haloalkyl.
 4. A herbicidal composition which comprises an effective amount of at least one compound according to claim 1 and an inert carrier and/or auxiliary.
 5. A method of combatting unwanted plant growth which comprises applying an effective amount of at least one compound according to claim 1 to said plants or to an environment where they reside.
 6. The method according to claim 5, wherein the unwanted plants are monocotyledons.
 7. The method according to claim 3, wherein the unwanted plants are dicotyledons.
 8. The substituted pyrazole derivative according to claim 1, whereinR¹ and R² together form the group --(CH₂)₄ --; R³ is Cl; R⁴ is H; R⁵ is CN; and R⁶ is ##STR115## 